not-os

kernel

$ nix-build -A kernel
/nix/store/h8b7wm2cgpgbdj37ic8j6p2m2yd0n6x1-linux-5.4.104

The kernel derivation results in an actual kernel, a bzImage file, but also in a set of kernel modules.

The modules are packaged in the shrunk derivation, which itself is used to create the initrd.